Apparatus for manufacturing gas



3 Sheets *Sheet 1.

(No Model.)

J. L. STEWART. APPARATUS FOR MANUFACTURING GAS. No. 584,713.

Patented June 16,1897.

(No Model.) 3QSheets-Sheet 2.

J. L. STEWART.

APPARATUS FOR MANUFACTURING GAS. No. 584,713. Patented June 15, 1897.

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J. L. STEWART. APPARATUS FOR MANUFACTURING GAS; No. 584,713. PatentedJune 15, 1897.

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ATENT APPARATUS FOR MANUFACTURING GAS.

SPECIFICATION forming part of Letters Patent No. 584,713, dated June 11897. Application filed April 19, 1890. Serial No. 348,644. (No model.)

To all whom it may concern:

Be it known that I, JOHN L. STEWART, a citizen of the United States,residing at San Francisco, in the county of San Francisco and State ofCalifornia, have invented certain new and useful Improvements inApparatus for Manufacturing Gas; and I do hereby declare the followingto be a full, clear, and exact description of the invention, such aswill enable others skilled in the art to which it appertains to make anduse the same.

This invention relates to the manufacture of heating and illuminatinggases by means of low-priced carbonaceous fuel in the form of dust orslack or cheap hydrocarbon oil in a cupola-generator provided withnumerous brick fines.

My present invention embraces certain improvements on the processes andapparatus described and claimed in my former applications for themanufacture of gasviz., Serial No. 227,537, filed February 14, 1887, andSerial No.24c7,605,filed August 22, 1887. These improvements relate moreparticularly to the methods and means for supplying the cupolageneratorwith properly proportioned and regulated quantities of air andcarbon-dust for heating up the brickwork lines of the cupola; also forsupplying properly proportioned and regulated quantities of steam andcarbon -dust to the heated decomposingchambers of the cupola forgenerating watergas.

The object of the invention is more particularly to supply thecarbon-dust and air in such proportions and'quantities as to secureperfect combustion and heat the cupola most economically and in theshortest time also to supply the carbon-dust and steam to the heateddecomposing-chambers in such proportions as to secure perfectdecomposition of the steam int-0 watergas without waste of carbon-dust.

The matter constituting my invention will be defined in the claims.

The construction and operation of my improved generator will now bedescribed wit-h reference to the accompanying drawings, in which Figure1 represents a vertical section of a cupola generatingfurnace withconnecting steam-boiler and water-heater, air-heater,

steam-engines,positive air-blower, and carbon-dust-feeding devicespartly in section and partly in elevation. Fig. 2 represents a verticalsection of acupola-generator of modified form, showing the connectingsteamboiler and the carbon-dust-feedingboxes, but

with theair-heater, engines, and blower omitted. Fig. 3 represents asectional detail, on an enlarged scale, of the dust-feeding andair-supply pipe. Fig. 4: represents avertical section of the governorfor controlling the flow of steam to the engine and the flow ofexhausted steam from the engine to the generator. valve. Fig. 6represents a face view of the valve-seat and ports.

The cupola-generator is built of brick with a lining of fire-brick,covered with a tight iron jacket and resting upon a suitable foundationin the usual manner. The cupola is provided at the bottom with thefuel-chamber A, having the usual grate and ash-pit. Above thefuel-chamber is provided a combustion-chamber B, having in its walls thetwoannular air-supply fines O 0, having narrow slits or ports 0 0opening into the interior of chamber B. The supply-pipe D for mixedcarbon-dust and air also connects with chamber B between the fines O 0.Above chamber B is provided a decomposing-chamber G, containing numerousfiues formed of refractory material, and above such chamber I provide asecond combustion-chamber 13, provided with annular air-fines F F,having ports opening into chamber B. The supplypipe D for mixedcarbon-dust and air also connects with chamber B between the fines F F.The second brickwork decomposingchamber G is constructed above chamberB, and above such chamber G, at the top of the cupola, I provide thethird combustion-chamber B, having in itswall an annular air-flue H,provided with ports openinginto the chamber B. The cupola is provided atthe top with the main outlet opening X, havinglid w. The ashpit, thefuel-chamber, and the combustion-chambers B B are provided with openingsand doors Y Y Y,Y, as shown. The top chamber B is provided with anopening Z, connecting by a pipe 5 with the airheater M. The ash-pit ofthe cupola is connected by a pipe P, having valve 19, with the Fig. 5represents a face view of the base of the tubular boiler I, having boxesi t" at bottom and top. The steam-drum J connects by pipej with the topof boiler I. The pipe r connects the top box 1" of boiler I with the box0 of Water-heater I, and the pipe m leads from the bottom box 0 of suchheater to the usual seal-box. A water-supply pipe n connects with thelower part of heater I, and a pipe 91 leads from the upper part of suchheater to the boiler I.

The positive air-blower K, operated by an engine L, forces air into thetubularair-heater M. The blower connects with the shell of heater M,above its bottom smoke-box r, so that the air to be heated shallcirculate around and between the tubes. The heater is provided at thetop with a smoke-box b, which is connected by pipe with the top of thecupola, and such pipe .2 is provided with a slide-valve m, which may beoperated by chains or ropes passing over pulleys,as shown. The pipe Kfor heated air leads from the top of air-heater M and extends downwardto near the base of the cupola, being provided with numerous branchpipes provided with valves for supplying air to the ash-pit andcombustion chambers. A branch pipe 7.", having valve f, leads from pipeK for supplying combustion-chamber B with hot air, and branch pipesprovided with valves cl d d lead from such pipe 7i; into the annularfiues F F and into the dust-supply pipe D. A valve 6 controls the fiowof hot air to combustion-chamber l3 and ash-pit. Branch pipes havingvalves a a lead into the annular flues C C, and branch pipe a leads intothe dust-supply pipe D. A branch pipe having valve 72, leads into'theash-pit.

The feed-boxes E E E for carbon-dust are mounted at the proper height,as shown, and are provided with spiral screw conveyors N N N, arrangedat their lower ends and proj ecting outward into the dust-supply pipes DD D". These dust-supply pipes D I) are elliptical in cross-section andare arranged with their greatest diameters in a vertical position, asshown in 3. The air-supp] y pipes connect at their under sides, and thetwo pipes open into a common chamber, so

that as the dust is conveyed" forward by the conveyer it is caught bythe air-blast entering below and carried directly into thecombustion-chamber. The shafts of the screw conveyers N, (be. extend outthrough the sides of boxes E and are journaled in suitable supports, andare also provided with fast and loose pulleys s s. The belt l connects apulley on the shaft of the engine with a pulley on the shaft 19, whichis also provided with a driving-pulleyw, which is connected above andbelow by belts r with the pulleys on the shafts of the spiral conveyersin boxes E E.

A large storage-tank T, Fig. 1, having inclined bottoms T, is providedfor supplying carbon-dust to the boxes E E. The tank T is provided witha spiral conveyer w in its bottom, extending out through the pipe V,

which connects directly with the top of dustbox E and by means of a pipeW, having a valve w",with the top of dust-box E. The shaft of the spiralconveyer 10 may extend through the top of box E and be journaled in asuitable support. It is provided with fast and loose pulleys 3s. Asimilarstorage-tan k (not shown) is also to be provided for supplyingcarbon-dust to box E and in practice would connect with the top of suchbox by means of pipe IV. The storage-tanks T may be located outside ofthe generator-building and provided with suitable covers. When it isdesired to fill the boxes E E with dust, the valve w" may first beopened and the conveyer w started in motion, when the dustwill pass downthrough pipe IV first into box E until it is filled. Then the continuedoperation of the conveyer will carry the dust into box E until it isfilled, after which the belt is shifted onto the loose pulley. Thestorage-tanks T are kept supplied with carbon-dust by means of anendless chain or belt provided with buckets similar to those used ingrainelevators.v

A portable upright engine L is set upon the upper floor of thegenerator-house for operating the dust-conveyer N in box E, and itsshaft, having a pulley, is connected by a belt 1' with shaft b, having adrivingpulley which is connected by a belt r with the fast and loosepulleys s s on the shaft of the spiral conveyer N. The dust-pipe D,leading from box E, connects with the steamjet-injector chamber R, whichconnects by pipe 10 with the chamber B at the top of the cupola and bythe return or circulating pipe R with combustionchamber B. A steam-pipeit leads from steam-drum J to the engine L and is provided with valve25. A branch steam-pipe a, provided with a valve, connects with pipe a,leading into injector R. The exhaust-steam pipe if, provided with valvei, leads from engine L down to a steamsuperheatin g chamber J, where thesteam is superheated, and such steam is returned by pipe u to theinjector-chamber R.

In case of a large gas-generator, where it may not be desirable orconvenient to furnish all the air by a single blower, two or moreblowers may be so connected by means of belts or gear-wheels as tooperate together and supply air the same as a single blower forcombustion of the powdered fuel, or a separate blower may be connectedwith each spiral conveyer for independently supplying powdered fuel toeach combustion-chamber. In every case the spiral conveyer is adjustedto the speed of the blower and engine, so as to supply a properproportion of airand carbon-dust. In practice the blower and its engineis provided with a governor such as used with the Roots blowers.

Instead of belts for operating the spiral dust-conveyers I may use gearwheels and pinions properly arranged for such purpose, and I also use aclutch in place of a loose pulley to throw the spiral conveyer into andout of gear, as required. In some cases the gear wheels and pinionswould be preferable, as with them there could be no slipping and failureto act, as in the case of the belts.

In connection with the steam-engine L for driving conveyer N andsupplying the proper proportion of dust and steam to the generator inmaking water-gas I prefer to use my improved steam-governor T.(Illustrated in Figs. 4, 5, and 6.) This governor is composed of avalve-chamber 1, the pistonchamber 2, containing the piston 3, and rod 4for supporting the weights 5, and nut 6, secured to the end of rod 4above a suitable support, and of the valve and its seat 8 and 9. Thepistonchamber 2 is provided with a packing for the piston 3, and astuffing-box is applied to the bottom of valve-chamber 1 for the passageof the valve'st-em 7. A collar (not shown) may be applied to thevalvestem 7 below the stuffing-box for limiting the upward movement ofthe valve. The valveseat 9, provided with suitable ports, is arrangedacross chamber 1, and the valve 8, constructed to register with theports of the valve-seat, is suitably connected to the valverod 7. Thepipe to, which supplies steam to the engines, is connected on bot-hsides of the valve-chamber 1, as shown. The supply-pipe it is connectedby pipe 10, having valve 1 with piston-chamber 2, and the exhaust-pipetis also connected by pipe 11, having valve y, with piston-chamber 2below the piston 3. In this governor the pressure can be regulatedeither from the supply or exhaust-steam pipe by opening either of thevalves y or y and shutting the other one.

In order to operate the generator shown in Fig. 1 for the manufacture ofheating-gas, supposing all the valves and doors are closed, I first openthe doors Y Y and the lid 03 at the top of the cupola and kindle a fireon the through the tubes of the air-heater.

grate in chamber A, to which fuel is fed till a good strong bed ofignited fuel is formed. Then the doors Y Y are closed. Lid :1; may alsobe closed and the products of combustion caused to pass through pipeinto and Theengine L and. blower K are now started, the belts all beingon the loose pulleys, and the fire urged by the blasts by opening valves0 a" h. After the fire is well ignited and chamber B heated I openaininjector valve a" and at the same time start the spiral clustconveyerN by shifting belt 0" onto the tight or driving pulley and shut off mostor all of the air passing through valve h. The spiral conveyer conveysthe carbon-dust into the injection-chamber D, where it is caught bytheair-blast and blown into the combustionchamber B, in which it isignited and in des'cendiu gis met by the streams of heated air ad mittedthrough valve a, annular flue O, and ports 0. Air may also be admittedthrough the annular flue C, so as to burn the gaseous products arisingin chamber B and thereby heat the flues an d refractory material inchamber G above. As soon as combustion-cham ber B has been sufficientlyheated the valve fin pipe 7; is opened, and also the valves cl cl d inthe branch pipes leading into the annular fines F F and into thedust-chamber D. At the same time the belt is shifted onto the tightpulley on the shaft of conveyer N in dustboX E and carbon-dust fed tothe injectorchamber D, from whence it is sprayed into thecombustiomchamber B by means of the air-blast passing through pipe cl.The dust and air are supplied in regulated quantities and in suitableproportions so as to effect an instantaneous and perfect combustion ofthe carbon. The operation of feeding and burning the carbon-dust bymeans of blasts of air is continued until the decomposing-chambers G Gare heated to the proper temperature for decomposing steam. Then theair-valvesfe h are closed, entirely shutting off the supply of air tothe cupola. The valves or a ct and 01 ct cl are in the first instanceadjusted to supply the proper volume of air, and after this may be leftin such position, as the closing of valves f e it entirely shuts off theair from the cupola. Lid 00 at the top of the cupola and also the valvemin pipe ,2, leading to the air-heater, are tightly closed. The belts rare also shifted onto the loose pulleys, so as to stop the feeding ofdust to the combustion-chamber. The valve 19 in the gastake-off pipe Pat the bottom of the cupola is now opened and the engine L started byopening steam-valves t i. The exhaust-steam passes from the engine downpipe 'tto a steam-superheater and returns in a superheated conditionthrough pipe to, passing into the injector-chamber R. I then start thespiral conveyor N by shifting the belt r onto the tight pulley 8,thereby feeding carbon-dust in regulated quantities into theejector-chamber R, where it is injected by superheated steam passingupward from pipe to and is blown up through pipe 11/ into chamber B atthe top of the cupola. The steam is thoroughly carbureted by thecarboirdust, and in the passage of the mixed dust and steam through theheated brick fiues I of decomposing-chamber G the steam is decomposedinto hydrogen and carbonic oXid.

In case bituminous-coal dustis used a percentage of light oarburetedhydrogen is also set free in the decomposing-chambers G. The mixed gasespass down through chamber G and finally through the bed of fuel inchamber A, where any carbonic acid that may be present is converted intocarbonic oxid. The hot gas finally passes off from the ashpit into andthrough the tubular steam-boiler and through the tubular water-heater tothe seal-box, from which it passes to the washer, scrubber, purifiers,and holder. The pipe R admits gases to injector-chamber R, preventingthe formation of a vacuum therein by means of the steam-jet. Thehot gaspassing mixed with the carbon-d u st.

sprayer D is arranged in front of the opening of pipe 10 in chamber Band is so formed as to receive the blast of carbureted steam and sprayit over the top surface of chamber B. After the generation of water-gashas been continued for some time and the temperature is so much loweredthat carbonic acid is shown by a suitable test to be present in the gasI stop the spiral dust-conveyer N by shifting belt r on to the loosepulley and shut off the steam by closing valves i t, then opening valvem in pipe 2', leading to the airheater, and close valve 19 in thegas-take-off pipe P. The cupola-generator is then heated up as in thefirst instance. At first valve It may be opened, admitting air to theash-pit for heating up the bed of fuel in chamber A, and then such valvemay be nearly or quite closed While the carbon-dust is being burned bysuitable blasts of air in combustion-chambers B B above the fuel. Instarting the operation of reheating the cupola, valve 9 may be openedfor a short time, admitting air through annular flue H and its ports forburnin g any carbon-dust that may have lodged in chamber B during theadmission of carbureted steam. Such dust having been consumed valve 9 isclosed. After the generator has been again properly heated the mingleddust and air are again shut off and the manufaeture of water-gas isresumed by the admission of carbuted steam, as before explained.

The most important and valuable features in my carbureted-steam and dustprocesses and apparatus are, first, the means for supplying carbon-dustand air in suitable proportions and regulated quantities, and, second,carbon-dust and steam in suitable proportions and regulated quantitiesfor the economical production of cheap fuel-gas from the cheapest kindsof carbonaceous material.

By means of my improved construction and arrangement of parts thehorizontal spiral conveyers and air-blower are propelled by the sameengine and so geared and adjusted that the proportions of air and dustsupplied to the generator continue the same whether the e11- gine be runfast or slow. The speed of the engine L is controlled by the usualgovernor P so as to maintain a uniform air-pressure on the air-valves,such as one pound to the square inch, more or less, but of sufficientpressure to spray and distribute the dust in the cupola. The revolutionsof the spiral conveyers are governed by the speed of the engine and sizeof pulleys on the spiral-conveyer shafts, counter-shafts, andengine-shafts. These parts are in the first instance adjusted to delivera certain quantity of dust to each cubic foot of air discharged into thecombustion-chambers B B, of such quantity as can be properly consumed ina given-sized generator. The proper proportions of air supplied throughvalves a a a and d d d for the perfect combustion of the carbon-dusthaving been ascertained, these valves are set in a proper position andare then left open in such position. A stop or check may be fixed toeach of the valves, so that in case they are closed they will never openfarther than the proper adjustment for the particular kind ofcarbon-dust being used. Should a change of material or dust be made, areadjustment of the air-valves can be easily made to suit the quality ofdust being used. The valves having been properly adjusted there isnothing for the gas-operator in charge to do but to open and close themain air-supp1y valves, keep the dust-boxes supplied with carbondust,and keep the engine an d blower running. Through the air-valves a d Isupply just sufficient air for properly spraying the dust and admit thelarger quantity for causing combustion through valves (1 a and d d. Theair admitted into the annular flues O O and F F is superheated and thendischarged in even streams into the chambers B B, causing instantaneousand perfect combustion of the carbon-dust without any waste, as isalways the case where too much or too little carbon is supplied.

After the generator is fully heated up very little coal needs to beadded to the bed of fuel on the grate, but, if desired, the fuel inchamber A may be freely burned in connection with the carbon-dustadmitted above.

The properly proportioned and regulated supply of steam and carbon-dustfor the manufacture of water-gas is effected in a manner similar to thatemployed in the admission of dust and air for heating the eupola. Thesteam, however, that is eventually used to generate water-gas is firstused to operate the engine that Works the spiral screw conveyer N fordelivering dust in the proper proportion to the decomposing-chamber ofthe cupola. The cupola having been heated and the valves properlyarranged for manufacturing Water-gas, the engine L is started by openingsteam-valves t t in the supply and exhaust pipes of the engine, the belt7'' is shifted onto the tight pulley of the spiralconveyer shaft, andthe steam and dust are supplied to the decomposing-chamber, as before.explained. The proper proportions and quantities of steam and dust aregoverned by the steam passing through the steam-cylinder of the enginethat operates the spiral dustconveyer, since each stroke of thesteam-piston measures a certain quantity of steam under a uniformsteam-pressure in such cylinder. The number of revolutions of the spiralconveyer is controlled by the speed of the engine in connection with thecounter-shafts, pulleys, and belts above described. The steam-pressurein the steam-cylinder is regulated by the governor T to any desiredpressure below that in the steam-boiler. For eX- ample, suppose thateach revolution of the spiral dust-conveyer N delivers one pound ofcarbon-dust into the injector-chamber R, and that twenty pounds ofcarbon-dust are required to each one thousand feet of gas generated, andthat the maximum production of gas in the generator is two thousandcubic feet per minute, then the speed of the spiral conveyer is to beforty revolutions per minute. Now suppose the capacity of thesteam-cylinder to be one cubic foot, and that the uniform steam-pressurein the cylinder is sixty pounds, and as one cubic foot of steam at sixtypounds pressure is equal to four cubic feet at atmospheric pressure, andas it requires about five hundred cubic feet of steam at the latterpressure to produce one thousand cubic feet of gas, then to produce twothousand cubic'feet of gas per minute will require one thousand cubicfeet of steam at atmospheric pressure, or two hundred and fifty feet atsixty pounds pressure. As each revolution of the driving-pulley on theengine measures two cubic feet of steam at sixty pounds pressure, thenthe speed of the engine should be one hundred and twenty-fiverevolutions per minute. With the above conditions it is easy tocalculate the dimensions of the pulleys so as to give forty revolutionsto the spiral eonveyer to every one hundred and twenty-five revolutionsof the engine per minute. These adjustments of parts, like those for airand dust, need to be made only once, after which they require no furtherattention except to see that the steam-pressure in the boiler is keptabove that required for the steam-cylinder of the engine. The speed ofthe engine is-regulated at valve t" by the operator, or, to start with,by the size of the nozzle on the end of pipe to delivering steam toinjector-chamber R.

No matter how fast or slow the engine is run the proportions of steamand carbon-dust continue the same, so that when the dues of thedecomposing-chamber are at a high heat, so as to rapidly generate gas,then the desired quantity of carbureted steam can be supplied by simplyopening steam-valve t a little more and gradually shutting off steam asthe heat in the generator is lowered, the proportions of steam andcarbon-dust continuing always the same. To effect a uniformsteam-pressure in the steam cylinder, 1 use my improved steam-valvegovernor connecting together the steam-inlet pipe and the exhaust-steampipe between the valve 2." and the engine,-so that the pressure in theexhauststeam pipe is practically the same as it is in the inletsteam-pipe between governor T", valve 15, and the engine, less thepressure necessary to run the engine and operate the spiraldust-conveyer N, which diiference in pressure would be nearly constantand should not make more than one or two pounds difference per squareinch. The steam-pressure in the cylinder can be adjusted or changed byadding to or removing weights from the steam-governor to any desiredpressure less than that in the steam-boiler. When, however, the pressureis changed, a readjustment of the speed of the carbon-dust con veyerwill be necessary. Supposing the steam-governor be set to maintain sixtypounds steam-pressure in the steam-cylinder, then, for accurate working,it is only necessary to maintain the pressure in the steamboiler abovesixty pounds. The exhauststeam after passing valve 15 may be passeddirectly into the steam-injector in chamber R, but when the carburetedsteam is delivered into the top chamber of the generator I prefer thatit be superheated.

It has heretofore been proposed to manufacture gas from steam andcarbon-dust in a generatingfurnace, but no provision was made forcontrolling or regulating the relative proportions of such dust andsteam, and the dust was therefore liable to be fed at one time in anexcessive quantity that is, a quantity much greater than that requiredfor decom posing the quantity of steam being suppliedresultin g inclogging the heating-fines formed in the brickwork and interfering withthe regular and systematic manufacture of gas. At another time adeficient proportion of carbon-dust would be fed as compared with thequantity of steam, and such steam would not therefore be properlydecomposed. This difficulty is especially present in intermittentwater-gas-gen eratin g furnaces where the temperature is constantlyvarying from a high degree at the commencement of each run to a lowerand lower degree toward the end of the run.

In such generating apparatus steam is always supplied rapidly and inlarge volume when the heat is high and is gradually reduced in quantityas the temperature is lowered. No provision, however, has heretoforebeen made for decreasing and regulating the volume or quantity ofcarbon-dust supplied to such furnaces in proportion to the varyingvolume of steam supplied thereto.

In my process of generating gas the carbondust and steam used are notonly supplied to the generator in the proper proportions and quantitywhen the temperature is high, but the relative proportion of each ismaintained substantially uniform, both decreasing in quantity alike asthe temperature of,

the furnace is reduced.

My steam-governor shown in Fig. 4 can also be operated so as to assistin proportioning the steam and carbon-dust supplied to the generator.For instance, supposing the steamboiler pressure to be one hundredpounds and the governor weighted to fifty pounds, and with thiscondition that there is too much dust being supplied to the amount ofsteam, then by adding more weights to the governor, thereby increasingthe pressure to sixty pounds, about one-fourth (i) more steam issupplied to each revolution of the screw conveyer. In a similar mannerthe proportion of steam may be reduced by removing weights from thegovernor, thereby decreasing the pressure. Y

When it is desired to manufacture illuminatinggas, it is only necessaryto spray in oil or benzin at any point in the lower portion of theheated fines or over the bed of fuel toward the latter part of the runafter the fire has partially cooled down, or the hydrocarbon oil may besprayed in with the carbon-dust in sufficient quantities to produce agas of the required candle-power.

All the steam-pipes connected with the steam supplied from the boiler tothe generator must be protected by asbestos or other suitable material,so as to prevent condensation in the pipes.

The cupola-generator shown in Fig. 2 is somewhat modified in itsconstruction and operation as follows: At its lower end it is providedwith a water-jacket A, surrounding the fuel-chamber, which jacket isconnected by pipes 00 as with the boiler I. The injector-chamber R andsteam-jet pipe 2/ are arranged to discharge directly into thecombustion-chamber B at about the middle of the cupola, while theexhaust-steam pipe '6, leading from the engine, is conducted directly tothe top of the cupola and the steam discharged into chamber 13', fromwhence it passes down through the highly-heated brick flues in chamberG, where it is highly superheated. This superheated steam combines withthe carbon-dust being blown into chamber B and the mixture passes downthrough the highly-heated lines in chamber G, where decomposition takesplace, and then the resulting gases pass through the bed of fuel outthrough the take-off pipe, steam-boiler, and water-heaterto theseal-box. By this method of conducting the operation the superheatedsteam either volatilizes or combines with all the carbon=dust andcarries it down to the fuel-chamber. The carbon-dust may also be sprayedinto chamber 13 directly over the surface of the fuel and steam admittedto the top of the cupola.

The stack above chamber B can be made of any desired height, so thatproducts of combustion may pass out at the opening X at a temperaturebut little above that of the steam in the boiler.

Smaller generators suitable for factories, 850., may be constructed witha single fuelchamber, one combustion-chamber l3, and one chamber G,filled with refractory material.

Having described my invention, what I claim, and desire to secure byLetters Patent, 1s-

1. A gas-generating apparatus comprising in combination agenerating-furnace, having a supply-pipe for mingled carbon-dust andsteam, a device for feeding carbon-d ust, a device for measuring andfeeding steam and mechanism connecting said devices for regulating thefeed of both the dust and steam in uniform proportions, substantially asdescribed.

2. A gasgenerating apparatus comprising in combination agenerating-turnace, a carbon-dust-feeding device, an air-feeding deviceand connecting mechanism-for regulating the feed of dust and airinproper proportions for heating the furnace; also a dustfeeding device, asteam measuring and feeding device and mechanism connecting said devicesfor regulating the feed of dust and steam in uniform proportions forgenerating gas, substantially as described.

3. In combination with the decomposingchamber of a cupola gasrgenerator,a carbondust feed-box and conveyor, a connected injector-chamber, anengine connected by suitable gearing with the dust-conveyor, and alsoconnecting by means of its exhaust-steam pipe with the injector-chamber,and a pipe connecting the latter chamber with the eupola, substantiallyas and for the purpose described.

t. The combination with a cupola-generator, an injector-chamber, havinga supplypipe and conveyor for carbon-dust and a steam-jet pipe, of adust-pipe leading from the discharge end of the injector-chamber intothe cupola and a return or circulating pipe leading from the cupola intothe inlet end of such injector-chamber substantially as and for thepurpose described.

5. In combination with the combustionchamber of a cupola-generator thetwo annular air-distributing t1 ues provided with ports arranged at topand bottom of such chamber, and a carbon-dust-supply pipe with conveyorand blast-pipe connecting directly with the combustion-chamber betweenthe annular air-distributing fines substantially as and for the purposedescribed.

6. The combination with a cupola gas-generator, a carbon-dust feed-box,a feed-pipe connecting it with the cupola-generator, and a screwconveyor arranged in such box and feed-pipe, of an air-blower, a pipeleading from such blower and connected with the discharge end of thedust-pipe below said screw conveyer, and a steam-engine connected bysuitable gearing with both the dust-conveyer and the air-blower forsupplying proper proportions of carbon-dust and air to thecombustion-chamber of the generator, substantially as described.

7. The combination with a generating-cupola of a carbon-dust feed-box, adust-conveyer and feed-pipe connecting said box with the cupola,asteam-engine, operating-gearing connecting said engine with saiddust-conveyer, a steam-supply pipe to the engine, and an exhaust-pipeleading therefrom to said dust-feed pipe connecting the feed box withthe cupola, and a steam-governor as T 0011- necting by separate valvedpipes with said steam supply and exhaust pipes of the engine, wherebythe relative proportions of steam and carbon-dust supplied to the cupolawill be constantly maintained, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN L. STEIVART. lVitnesses:

ROBERT A. MeCALL, C. L. GODDARD.

IOC

